small intestine
the __ is the site of most vitamin absorption in the body
coenzymes
most B vitamins are essential for the metabolism of energy yielding nutrients. They perform this function by binding to and promoting the activity of enzymes. When B vitamins perform this way, they are __?
fortified; folate
folate deficiency symptoms are less of a problem recently because grain products have been __ with __
do not
vitamins __ provide energy
longer
it generally takes __ to develop a deficiency of fat-soluble vitamin than a deficiency of a water soluble vitamin
thiamin
Berberi is a disease caused by lack of __ in the diet
light
riboflavin is most easily destroyed when exposed to __
pellagra
disease caused by a niacin deficiency
tryptophan
niacin can be synthesized in the body from the amino acid __
egg whites
biotin is tightly bound by avidin, which prevents absorption of the vitamin. Avidin is commonly found in __
CoA
pantothenic acid is part of the molecule __
cobalamin
another name for vitamin B12
vitamin B6, vitamin B12, folate
an elevation in homocysteine has been associated with an increased risk of cardiovascular disease. In clinical studies, which vitamins have been shown to decrease levels of homocysteine in the blood?
folic acid
increased amounts of which vitamin are recommended during pregnancy to reduce incidences of abnormalities in the brain or spinal cord of the developing baby?
B12; nerve damage
high intake of folate is cause for masking a __ deficiency, giving rise to permanent __
rapidly dividing cells
folate's role in DNA synthesis makes it particularly important in
vegan
meeting B12 needs from the diet is especially difficult for people following a strict __ diet
R-proteins, intrinsic factor, adequate stomach acid
absorption of B12 is dependent upon:
pernicious anemia
B12 deficiency caused by a deficiency of intrinsic factor results in:
choline
__ is not classified as a vitamin
iron
consumption of orange juice enhances the absorption of which mineral?
anencephaly
a birth defect due to failure of the neural tube to close that results in the absence of a major portion of the brain, skull, and scalp
antioxidant
a substance that is able to neutralize reactive oxygen molecules and thereby reduce oxidative damage
ariboflavinosis
the condition resulting from a deficiency of riboflavin
ascorbic acid
the chemical term for vitamin C
atrophic gastritis
an inflammation of the stomach lining that results in reduced secretion of stomach acid and bacterial overgrowth
berberi
the disease resulting from a deficiency of thiamin
bioavailability
a general term that refers to how well a nutrient can be absorbed and used by the body
cobalamin
the chemical term for vitamin B12
coenzymes
small nonprotein organic molecules that act as carriers of electrons or atoms in metabolic reactions and are necessary for the proper functioning of many enzymes
collagen
the major protein in connective tissue
dietary antioxidants
a substance in food that significantly decreases the adverse effects of reactive species on normal physiological function in humans
dietary folate equivalents
the unit used to express the amount of folate present in food.
enriched
refers to a food that has had nutrients added to restore those lost in processing to a level equal to or higher than originally present
fat-soluble vitamins
vitamins that dissolve in fat
flavin adenine dinucleotide and flavin mononucleotide
the active coenzyme forms of riboflavin. Structure allows them to pick up and donate hydrogens and electrons in chemical reactions
folic acid
the monoglutamate form of folate, which is present in the diet in fortified foods and supplements
fortification
a term used generally to describe the process of adding nutrients to foods, such as the addition of vitamin D to milk
free radical
one type of highly reactive molecule that causes oxidative damage
intrinsic factor
a protein produced in the stomach that is needed for the absorption of adequate amounts of vitamin B12
macrocytes
larger than normal mature RBCs that have a shortened life span
megaloblastic anemia
a condition in which there are abnormally large immature and mature RBCs in the bloodstream and a reduction in the total number of RBCs and the oxygen-carrying capacity of the blood
megaloblasts
large, immature RBCs that are formed when developing RBCs are unable to divide normally
neural tube defects
abnormalities in the brain or spinal cord that result from errors that occur during prenatal development
niacin equivalents
the measure used to express the amount of niacin present in food, including that which can be made from its precursor, tryptophan
1; 60
One NE is equal to __mg of niacin or __mg of tryptophan
nicotinamide adenine dinucleotide
the active coenzyme forms of niacin that are able to pick up and donate hydrogens and electrons. They are important in the transfer of electrons to oxygen in cellular respiration and in many synthetic reactions
oxidative damage
damage caused by highly reactive oxygen molecules that steal electrons from other compounds, causing changes in structure and function
oxidative stress
a condition that occurs when there are more reactive oxygen molecules than can be neutralized by available antioxidant defenses. It occurs either because excessive amounts of reactive oxygen are generated or because antioxidant defenses are deficient
parietal cells
large cells in the stomach lining that produce and secrete intrinsic factor and hydrochloric acid
pellagra
the disease resulting from a deficiency of niacin
pernicious anemia
an anemia resulting from vitamin B12 deficiency that occurs when dietary B12 cannot be absorbed due to a lack of intrinsic factor
pro-oxidant
a substance that promotes oxidative damage
provitamin
a compound that can be converted into the active form of a vitamin in the body
pyridoxal phosphate
the major coenzyme form of vitamin B6 that functions in more than 100 enzymatic reactions, many of which involve amino acid metabolism
pyridoxine
the chemical term for vitamin B6
scurvy
the vitamin C deficiency disease
spina bifida
a birth defect resulting from the incorrect development of the spinal cord that can leave the spinal cord exposed
thiamin pyrophosphate
the active coenzyme form of thiamin. It is the predominant form found inside cells, where it aids reactions in which a carbon containing group is lost as CO2
vitamins
organic compounds needed in the diet in small amounts to promote and regulate the chemical reactions and processes needed for growth, reproduction, and maintenance of health
water-soluble vitamins
vitamins that dissolve in water
wernicke-korsakoff syndrome
a form of thiamin deficiency associated with alcohol abuse that is characterized by mental confusion, disorientation, loss of memory, and a staggering gait